Geocell instead Geogrid to enhance the subgrade

One day, I received an inquiry from a customer who wanted to use Geogrid or Geocell to enhance their road subgrade. More details, please check below:

#Information from customer:

We are looking in to a project where a construction company has to ensure good quality subgrade (material from neighborhood is not A2-4 class, it is an A3 or A4 ) for a road project. Using either geocell or geogrid (as you propose or provide pricing for both options) and later use another product to enhance the quality of asphalt pavement using geogrid between binder and wearing asphalt courses.

Can you please provide indicative price CFR xxx for ( 200,000 m2) square meters of geogrid,
tensile strength 40 kn/m2 in each direction to reinforce the soil.

Also provide packaging details and technical data sheet.

#My answer:

Thanks for your below inquiry.

We only supply Geocell, so we can’t provide you with the proposal and prices for both options(Geocell and Geogrid).

Do you have more information regarding your project, like subgrade strength, vehicle type, loading capacity, traffic patterns, and type of infill material? If you can give us this information, we can recommend the suitable Geocell type and quote the exact Geocell price accordingly.

#Information from customer:

Dear Claire
The reply to our request was as follows:

•Our subgrade is usually a  material  of  “A4” AASHTO  classification, at times it is A3 but it is generally weak,
•Our vehicle type is usually heavy load trucks that are capable of transporting 120 ton loads.
•After reinforcing subgrade we intend to use A2-4  material as a subbase material 20 cm thick and then another layer of base coarse material 45 cm thick layer and then comes asphalt (binder layer 8 cm and then wearing layer of 6 cm thickness )

#My answer:

Dear Theodoros,

Thanks very much for your valuable information.
Please check my answers as follows:

1, Based on all your project information, Geocell 200-356(height 200mm, welding distance 356mm) should be the most suitable type. But please let me recheck with our engineer tomorrow, after getting his confirmation, then I will quote the price to you accordingly.

2, Attached our Geocell selection guide for your reference.

3, “After reinforcing subgrade, we intend to use A2-4  material as a subbase material 20 cm thick.” – Regarding this, in my opinion, you can use 20cm Geocell and infill the A2-A4 material as the subgrade directly. Geocell is 3-dimensional network, one of the advantages is that can use lower quality/cost infill materials, at the same time can reach good strength. Below is the equivalent table for your reference. For more details, you can check the Geocell design and installation guideline in attachment.

I will also check this question with our engineer tomorrow, and I will let you know the suggestions from our engineer accordingly.

#After checking with our engineer, please check my answers:

I discussed all your project information with our engineer. Please check our answers as follows:

1, Due to your existing subgrade is too weak, our engineer said he is afraid that the Geogrid can’t affect, because the Geogrid is only a two-dimensional structure, and can’t restrict the infill material. Geocell is a three-dimensional structure that can restrict the infill material well.

2, We want to know if your design “After reinforcing subgrade we intend to use A2-4  material as a subbase material 20 cm thick and then another layer of base coarse material 45 cm thick layer and then comes asphalt (binder layer 8 cm and then wearing layer of 6 cm thickness )” is based on only install 1 layer Geogrid to enhance the subgrade?

If your above design based on only install 1 layer Geogrid to enhance the subgrade, after changeing to use 200-356mm Geocell, you can reduce the total height of 40cm(20cm+20cm), the first 20cm is(we intend to use A2-4  material as a subbase material 20 cm thick), and the second 20cm is (then another layer of base coarse material 45 cm thick layer).

3, All the above recommendations are based on our full experience in the Geocell field, it is better to be calculated by a professional engineer to avoid any potential problem.

I will quote our Geocell HF200-356 price in the next email separately.
Thanks in advance : )

Any further questions, let Claire know freely. I’m the Geocell expert to answer any of your questions.

Based on my 15 years of experience in the Geocell field.

Replace the concrete frame system by Geocell on steep slope

Recently, I received a new inquiry. The customer wants to replace the concrete frame system by geocell on steep slope. Let’s check the customer’s requirements and questions together, and also check our answers for their design.

We are designing a solution for slope protection that using the concrete frame + stack soil bag for the vegetation. Is it possible to replace the concrete frame system by geocell? If yes, please suggest us your design. The total surface area is 11.000sqm. I’m thinking of using 15cm depth geocell for confining the soil. Also send us your material price for budget estimation.

Slope height 12m

Slope angle 45 deg

Soil is: Weathered sandstones layer

The concrete frame size is 2mx2m

The beam section is 20x20cm

My answer: I checked your attached design carefully. And I just got a new customer in Singapore, they are doing a similar project, same design as like your project.

I want to confirm one question: you want to install the geocell inside the concrete frame or just on top of the concrete frame?

And our customer told me their slope height is also 12m.

Their concrete frame size is 1.5mx1.5m

The beam section is 30x30cm

The Geocell they design is height 150mm, welding distance 400mm.

We don’t want to use the concrete frame. Is only geocell ok? I mean we want to replace the concrete frame system (with soil nail & soil bag) by the geocell and confined soil for the grass. But our slope is 45degree. Is it too steep for keeping top soil & grass? And please send me your installation guidance on slope.

My answer: Some slope designs don’t have concrete frame, and we have did several slope projects in your country.

Based on all the information you provided, we recommend to use our Geocell HF150-445(height 150mm, welding distance 445mm) with tendon system. And I will send you 2 projects for steep slope for reference.

Yes, I also want to know the detail of tendon system… How to keep the geocell & top soil on that 45deg slope.

Because in our project, the subgrade is weathered sandstones, impractical for the J-pin anchor. So it may need the tendons. And How to secure the geocell panels in the top of slope?

My answer: Use Deadman + Tendon design system. If can’t use J-pin, then only can use Tendon. And Tendon is very important!

For How many cells we put 1 tendon clip? And how is the spacing of tendons? Every cell need 1 tendon?

After I checked with our engineer, we give below 4 advices to our customer:

1. Install the geocell backward at least 50cm from the slope crest, 80cm better.
2. The tendon must be tied to the deadman and extended at least 1-1.5m backward.
3. Use a tendon for every other cell.
4. Use a tendon clip for every 4 cells(0.288×4=1.15m) or 5 cells(0.288×5=1.44m).

If you have similar projects that want to use Geocell, please let us know more information of your project. After our evaluation, we will advise you the most correct design and recommend most suitable Geocell type, also quote the best prices to support you.

Any further questions, let Claire know freely. I’m the Geocell expert to answer any of your questions.

Based on my 15 years of experience in the Geocell field.

Use Geocell to Protect the Geomembrane in Lagoon

In Apr. 2024, I received an email from one of my old customers in Peru, and he needed me to help to check a design for their lagoon project. And he also wants me to help to choose the best option and tell him the reason. For more details please check below information:

Dear Claire:

After several months I’m giving you some information, we are interested in knowing your criteria.

The project is to waterproof a lagoon with Geomembrane and place Geocells on the edge. Please review the 3 drawings and tell me your technical opinion of which one you consider better.

Hope to hear from you soon.

Best regards,

We have two customers in Vietnam who did similar projects in the year of 2019 and 2021, they used our Geocell HF100-660(height 100mm, welding distance 660mm) to protect the edge of the Geomembrane. If you want more information, please contact Claire directly for more design drawings.

Any further questions, let Claire know freely. I’m the Geocell expert to answer any of your questions.

Based on my 14 years of experience in the Geocell field.

How to Fix Geocell on Slope Protection Projects?

When HDPE Geocells are used on slope protection projects, the reinforcement is very important. In this article, I will show you the full information of Geocell slope protection reinforcement. First is the material that we will use to fix Geocell on a slope. Second, we should know the length & space requirements for the Geocell pins. Third, I will recommend 2 ways that how to fix Geocells on the top of the slope.  In the end, we should use tendons on very steep slopes. Let’s start now.

1, Use what to fix the Geocells on the slope?

You have 2 choices, one method you can use 12-14mm rebar as the anchor and use our anchor head together, please check the photos of our anchor and anchor head.

Or you can use J-pin directly, we don’t supply J-pin, you can buy 12-14mm rebar in your local market, and then ask the manufacturer to produce them into J-shaped. Use J-pin, then no need to buy anchor head. Most of our customers in South-east Asia use J-pin directly, they don’t buy anchor head.

2, The length and space requirements for Geocell Pin

The length and space requirements for Pin should based on the slope rate and soil property, we have a standard for this, please check the details I organized below.

3, From where to fix?

For Geocells used on slope protection projects, it is better to design a trench or deadman at the top of the slope. As in below photo:

If not have a trench or deadman design, to prevent landslides in the future, we’d better lay more area on the top of the slope, our engineer said for a 1:1 slope it is better to lay 80cm on the top, at least 40-50cm. As I marked on below photo:

4, Use Tendons on steep slopes.

On a steep slope, it is better to use Tendon. The durable Nylon tendon is very helpful in securing panels in place. Geocell panels include two slots designed to aid in attaching and feeding tendons through the panel walls. Tendons run through the length of each panel to help affix panels to the side of the slope for a more secure installation.

Regarding more information of Geocells are used on very steep slope, please check my another article here: Geocell for Steep Slope Protection.

Any further questions, let Claire know freely. I’m the Geocell expert to answer any of your questions.

Based on my 14 years of experience in the Geocell field.

In Oct. 2023, I shipped 5600m2 of our Excell Geocell HF50-330(height 50mm, welding distance 330mm) to Germany, that our customer use them for horse farm trails installation, and now he has done the installation and feedback come comments to me. Please check below information:

Dear Claire,

thank you for your message. We indeed now finished applying the first 200m² and it really all worked perfectly. It was quick and easy to do and the result is very good.

In the end it saves you having to dig very deep and put a lot of gravel into it.

Why Use HDPE Geocell on Horse Farm Trails?

HDPE Geocell is a three-dimensional cellular structure made of high-density polyethylene(HDPE). These interconnected cells create a stable, load-bearing surface that can be filled with various materials, such as soil or aggregate. The application of HDPE Geocell on horse farm trails offers several advantages:

Enhanced Load Distribution: Geocells distribute the load of hooves and machinery more effectively than conventional methods, preventing the formation of ruts and reducing soil compaction.

Erosion Control: By stabilizing the soil, geocells mitigate the risk of erosion caused by rainwater runoff.

Improved Drainage: Geocells allow water to infiltrate the soil, reducing surface runoff. This helps maintain the integrity of the trail during wet conditions, preventing the formation of muddy or impassable areas.

Maintains Surface Integrity: Geocells prevent the displacement of fill materials, ensuring the trail surface remains even and stable over time.

Installation Process 

Site Preparation:
Clear the trail area of any debris, vegetation, or rocks that may interfere with the installation process.

Laying Geocells:
Expand the geocells on the prepared surface, and use connection keys to connect them together, making sure they fit together securely.

Fill Material:
Depending on the specific requirements of the trail, fill the cells with a suitable material. This can range from compacted soil to aggregate.

Compaction:
Compact the fill material using a mechanical compactor to achieve the desired trail surface density.

Regarding the infill material, our customer infill below materials for your reference:

We filled the cells with „Split 8-16mm“, added 3cm „Mineral mixture 0-16mm“, shaked/compacted this and then added 10-15cm washed sand (0-3mm) on top of it.

The Results

The application of HDPE Geocell on horse farm trails has a lot of advantages:

Reduced Erosion: Geocells have proven highly effective in preventing erosion, ensuring that trails remain smooth even during heavy rainfall.

Improved Safety: Stable, even surfaces reduce the risk of tripping or slipping for both horses and riders.

Enhanced Drainage: Geocells promote natural drainage, reducing the accumulation of water and minimizing the formation of mud patches.

Long-Term Cost Savings: Geocells reduce the need for frequent maintenance and repair, leading to lower long-term operational costs for the farm.

Any further questions, let Claire know freely. I’m the Geocell expert to answer any of your questions.

Based on my 14 years of experience in the Geocell field.

Use HDPE Geocell and Coir Mats Together for Slope Protection

Some of our customers use HDPE Geocell and Coir mats together for slope protection, this method not only provides slope stability but also can promote sustainability.

In this article, I’d like to explore the functions of HDPE Geocell and coir mats individually, and then we will research the effects that installing them together in slope protection projects.

HDPE Geocell: Reinforcing the Foundation

HDPE Geocell is a three-dimensional honeycomb-like structure made from high-density polyethylene. These cells are interconnected and filled with soil, effectively creating a stable platform that distributes loads evenly. When installed on slopes, HDPE Geocell confine the soil within the cells, preventing erosion, and providing reinforcement against gravity and hydraulic pressures.

Functions of HDPE Geocell:

Soil Confinement: Geocells hold soil in place, preventing them from being washed away during rainfall.

Load Distribution: By spreading the load over a larger area, geocells reduce pressure on the underlying soil, preventing compaction and settling.

Erosion Control: The cellular structure acts as a physical barrier against erosive forces, maintaining slope integrity over time.

Vegetation Support: Geocells create a stable substrate for vegetation, allowing plants to take root and further stabilize the slope.

Coir Mats

Coir mat is a natural erosion control product made from coconut fibers. It provides a biodegradable and sustainable alternative to synthetic materials. This matting is widely used in erosion-prone areas due to its remarkable ability to retain moisture, suppress weed growth, and provide a stable medium for vegetation establishment.

Functions of Coir Mats:

Erosion Control: The fibrous structure of coconut matting helps to absorb and disperse water, preventing soil erosion and surface runoff.

Moisture Retention: Coir fibers retain moisture, promoting healthy plant growth and reducing water requirements for established vegetation.

Weed Suppression: The matting acts as a natural weed barrier, allowing desirable plants to flourish while inhibiting weed growth.

Biodegradability: Coconut matting breaks down naturally over time, enriching the soil with organic matter and reducing the need for removal after slope stabilization.

Combining HDPE Geocell and coir mats can maximize the benefits of both materials, which can create a cost-effective, sustainable and eco-friendly solution for a wide range of projects.

Any further questions, let Claire know freely. I’m the Geocell expert to answer any of your questions.

Based on my 14 years of experience in the Geocell field.

Geocell for Steep Slope Protection

Geocell can be used on very steep for slope protection, like a slope angle of 75°. When choosing the Geocell type, we should pay attention to 3 factors:

1, The Geocell height should be no less than 150mm, it is better to use 150mm or even 200mm.

2, On a steep slope, you should use Tendons to transfer the load.

3, Must use deadman design on the top of the slope.

Geocell Types for Steep Slope Protection:

Based on our experience, most customer choose below 4 types for their Geomembrane protection:
HF150-445, Height 150mm, welding distance 445mm, textured and perforated type.
HF200-445, Height 200mm, welding distance 445mm, textured and perforated type.
HF150-660, Height 150mm, welding distance 660mm, textured and perforated type.
HF200-660, Height 200mm, welding distance 660mm, textured and perforated type.

A case study from Pakistan, use our Geocell HF150-445 for their steep slope protection.

As for more installation details for  Geocell on steep slope projects, you can check the below video.

https://www.vidio.com/watch/144779-krakatau-posco-geocell-slope-protection

Any further questions, let Claire know freely. I’m the Geocell expert to answer any of your questions.

Based on my 14 years of experience in the Geocell field.

Geocell Channel for Rainwater Drainage

Let’s check a case study from one of our customers, who want to use Geocell to build rainwater drainage channels:

Good afternoon.

We need to quote geocells for the construction of rainwater drainage channels with concrete.

The height of the geocell must be 75 and/or 100 millimeters, please inform the width and length of the rhombus of the cell, as well as the maximum size of the piece of geocells. Initially we need to quote 200,000 m2.

This is the design of the drainage channels and their dimensions, as you can see it is a significant number of square meters. Please check your prices since the amount originally quoted is above market prices.

Please also provide us with A and B in mm, for 75 mm and 100 mm height. Also please provide N and M in cells and mm.

Question: What is the welding distance?

Dear Sir,

For Geocell welding distance, we can produce from 250mm to 1000mm, but regular types are just 330mm, 356mm, 445mm, 660mm, and 712mm.

330mm and 356mm mainly be used on soil stabilization/ load support projects.
356mm mainly be used on channel protection projects.
445mm mainly be used on slope protection or erosion control projects.
660mm and 712mm mainly be used on retaining wall projects.

But different projects use different Geocell types, for channel protection as in your project, some customers also use Geocell welding 356mm or 445mm. So it is better to confirm the exact specifications you designed, then I can quote the exact and best price to you.

A and B are fixed, when welding distance is fixed, it has nothing to do with the height.
For welding distance 356mm, AxB=260x255mm
For welding distance 445mm, AxB=320x288mm

N and M, no matter in cells or m, both can produce as per your request, if your project need size 5x8m/pc, then we can produce to close this size.
Our regular size is as follows:
For welding distance 356mm, MxN=2.34×7.65m
M=9 cells, N=34 cells
For welding distance 445mm, MxN=2.56×9.8m
M=8 cells, N=34 cells

Can you understand all the above information now?
Thanks for your time.

Dear Claire:

Attached we send the translated document. We need your company’s engineering department to be able to work with these figures to give us a complete quote.

Kind regards,

Dear Gerardo:

I have checked all your documents and figures with our engineer, and we still have several questions want to check with your technical person, which is more helpful to confirm the best suitable Geocell type and quantity, please check as follows:

1. Channels for storm drainage. These are simple mus, and can be from 75 to 100 mm. We need that reviewing the design, and you suggest us, which one to use.
For these channels we need to quote 340,514 M2.

# For storm drainage channels, we need to know:
1, Your subgrade type, which means your channels are newly dug or already existing?
2, The surface run-off velocities, also can called peak flow velocities? 
3, Your infill material, will infill concrete or gravel?

These 3 questions are important, please check and advise, then we can recommend and quote the best suitable Geocell type.

Answers from customer:

1, R. Channels are new.
2, R. high speed will be 4,8 meters per second, low speed 2,8 meters per second
3, R. infill Will be concrete H18.

Dear Gerardo,

I checked all your answers and discussed them with our engineer, we have another 3 questions as follows:

You shared your channel’s traditional construction photos with me before,
1, What’s the thickness of your concrete pouring?
2, What is laid under the concrete? Is it fiberglass geogrid composite geotextile? or polyester geogrid composite geotextile?
3, For your new geocell design, will you also lay fiberglass geogrid composite geotextile under the Geocell? Due to your channel is new, so must use Geotextile to prevent the settlement.

Get these 3 answers, then we can confirm the channel Geocell height for 75mm or 100mm.

Answers from customer:

1, 10 centimeters
2, Polyester or fiber geotextile, any of the two. Additionally, it has an 8-millimeter electro-welded iron mesh with a spacing of 15 centimeters.
3, Yes, geotextile will be placed in the sector where the concrete is poured. Additionally, drains are placed on the floor and on the walls, to avoid the pressure of the phreatic level, in the places that are required.

Finally, we recommend Geocell welding 445mm, height 100mm, seam peel strength 10KN/m, GB standard is ok.

As for the detailed size, I organized a file for the customer, if you want to know more details, please contact Claire to get it directly.

Any further questions, let Claire know freely. I’m the Geocell expert to answer any of your questions.

Based on my 14 years of experience in the Geocell field.

Geocell path in the forest

After a long period of sun and rain, the path in the forest has been eroded, making it difficult to pass. Government departments urgently need to build a new road.

The width of the path is less than one meter, and large construction equipment cannot be used in the forest, only small equipment can be used for operation.

Therefore, HDPE Geocell is the best choice, because it is very easy to construct, simple and fast, and does not require large equipment.

A 2-tonne excavator with operator excavating new track in order to place Excell Geocell. Soil is being dug and loaded into the self-loading tracked dumper.

Excell Geocell is being installed into the excavated path, type is 200-356, height 200mm, welding distance 356mm, textured and perforated type. And PET nonwoven Geotextilea are installed under the Geocell for reinforcement and isolation.

The infill material we choose is gravel, size 2-5cm. Gravel is being loaded into the Geocell via the self-loading tracked dumper. Once the cells are filled and the gravel compacted, the Geocell constructed base is ready to withstand heavy traffic loads.

The path is complete, gravel compacted into Excell Geocell and now it is ready for use.

Any further questions, let Claire know freely. I’m the Geocell expert to answer any of your questions.

Based on my 14 years of experience in the Geocell field.

Use HDPE Geocell to protect the slope of shrimp pond

I receive an inquiry from an old customer in the year 2019. They want to use our HDPE Geocell to protect the slope of their shrimp pond.

Dear Claire,

Besides drainage system, we are now studying to use geocell for slope protection. Please find attached files some photo of shrimp pond.

In below picture, blue line is current ground level. Red line is new road design with slope 1/1.5. The water in shrimp pump is just up and down, with flow velocities almost zero. However, we are afraid of erosion, sliding of slope, rains…. can progressively erode the slope. Please advise us on this matter. Should we use or not?

In your experiences, how length is the slope should we use Geocell.

Thank you.

Dear Sir,

Yes, the widest application for Geocell is slope protection. And I checked your attached photos carefully, it is suitable to apply Geocell on shrimp pond slope.

According to your slope ratio 1:1.5, Geocell height of 100mm is suitable, and we recommend welding distance 445mm or 660mm, both are suitable.

One of our customers in Vietnam did the same project last year, they use our HF100-660-1.5(height 100mm, welding distance 660mm, textured 1.5mm) on their pond, please check their construction photos in the attachment.

Any further questions, let Claire know freely. I’m the Geocell expert to answer any of your questions.

Based on my 14 years of experience in the Geocell field.